Due to the complexity of large-scale commercial refrigeration devices, these devices usually require regular maintenance and repair by professional personnel or require on-site repair by professional personnel when an error is reported due to a fault. However, maintenance personnel having different working experience, whether they are engineers hired by companies using the devices or engineers dispatched by device suppliers, may have different maintenance results. It may be difficult for some novice engineers to find fault causes of field devices and corresponding repair means. Even if the novice engineers communicate with senior engineers over the phone or network, it is still possible that the device fault cannot be resolved or a long time needs to be taken to resolve the problem due to unclear description or misunderstanding. This will greatly increase the shutdown time of the refrigeration device, thus causing poor use experience and after-sales service experience for device users.